Accurate and predictive first-principles calculations of spectral properties of materials, such as the band gap of semiconductors, are key to understanding, discovering and designing materials for countless applications including electronics, energy harvesting, and photonics.
In spite of the enormous theoretical progress and the exponential growth of accessible computing power over the last fifty years, such simulations are still challenging in many ways. Established methods, based on Feynman diagrams, are limited by their complexity and computational cost, and often neglect a consistent treatment of spin-dependent interactions. This is particularly relevant if considering spin-orbit coupling, a relativistic effect that is strong in presence of heavy chemical elements and often play a major role in cutting-edge scientific or technological applications.
In a new article just published in the journal Physical Review Research, Antimo Marrazzo from Scuola Internazionale Superiore di Studi Avanzati in Trieste, Italy, and Nicola Colonna, from the Paul Scherrer Institute in Villigen, Switzerland, advocate for a paradigm shift by introducing a new functional approach that allows calculating band structures of semiconductors in a simple way and at low computational cost, even in presence of spin-orbit coupling or complex magnetic configurations. This development will make computational screenings of materials databases much more efficient and accurate, and enable simulating complex materials under more realistic conditions, such as in presence of defects or at finite temperature.